1. Field of the Invention
The present invention relates to a blur correction device installed in an electronic apparatus typified by an image pickup apparatus such as a digital camera and an image output apparatus such as a display and a printer, a blur correction method thereof, and an electronic apparatus including the blur correction device. Moreover, the present invention also relates to an image file used in the electronic apparatus and an image file creating apparatus configured to create such an image file.
2. Description of the Related Art
Image information piece created with an image pickup apparatus such as a digital camera sometimes suffers from image degradation due to a shake of the image pickup apparatus during its exposure period. In many cases, an image pickup apparatus is shaken by user's hands movement, that is, by the jiggling of user's hands supporting the image pickup apparatus during the exposure period. Even if a user picks up images with the utmost care, such an apparatus shake is difficult to prevent completely.
For this reason, blur correction processing has been heretofore carried out to obtain a clear image. In the blur correction processing, an apparatus shake itself is reduced when the shake occurs during an exposure period, and degradation of an image caused by the apparatus shake is corrected after the image is picked up. Examples of this blur correction processing method include an optical correction method and an electronic correction method. With the optical correction method, a shake of an image pickup apparatus is cancelled out with an optical system such as a lens and an image pickup element driven in a direction of offsetting the shake while shake detection sensors such as an angular velocity sensor and an acceleration sensor are detecting the shake of the image pickup apparatus. In contrast, with the electronic correction method, a picked-up image information piece is analyzed to figure out blur components generated during the exposure period, and then the image information piece is corrected by use of the figured-out blur components.
In the case of using the optical correction method, however, a complicated and large blur correction device for driving an optical system needs to be mounted in an image pickup apparatus since correction must be carried out during shooting. In addition, an image pickup apparatus using the optical correction method requires high power consumption for driving an optical system and accordingly suffers from a problem of heavy battery consumption.
In contrast, in the case of the electronic correction method, a configuration of an image pickup apparatus can be simplified and downsized, and the correction processing can be carried out even in a printer or a display that does not perform an image pickup operation. This is possible because the correction processing can be performed on an image after the shooting. However, the electronic correction method has problems that it takes long time to analyze and process an image information piece, and that it is so difficult to analyze proper blur components in an image information piece that the image information piece may not be corrected sufficiently.
With this regard, in order to solve this problem, the inventors of the present application have proposed a blur correction device using an image restoration-based correction method (see Japanese Patent Application Publication NO. 2006-129236). In this blur correction device, a camera shake sensor measures an angular velocity or the like of a camera during the shooting to obtain a camera shake signal, and the image information piece is corrected based on this camera shake signal after the shooting.
Use of this image restoration-based correction method allows the configuration of an image pickup apparatus including a blur correction device to be simpler and more downsized than that using the optical correction method. In addition, the use of the image restoration-based correction method can achieve high improvement in the quality of corrected image information piece and allow a blur correction device to perform the correction operation at high speed in comparison with the case of using the electronic correction method.